There are many reasons why children of alcoholics and drug addicts also end up abusing alcohol and drugs as well.

Mother's that abuse alcohol and/or drugs while pregnant will most likely have babies that are born already addicted to the substances they (the mother) are abusing ... These babies have to go through detox as soon as they are born.

Some kids are able to overcome it, but most are not as the monkey has already been put on their back long before they had the choice to choose to "Just Say No" to alcohol and drugs.

Also, some parents think it's funny to let their toddlers and children ingest alcohol and drugs and laugh at the kids when they get tipsy, drunk or stoned on the substances they (the parents) are abusing.

That to me is a very sick and evil thing to do to a child.

Oh!, and there are also parents that use their children as mules, dealers and runners when the parents manufacture, sale and distribute such substances illegally, and most often these children grow up to continue doing what it is they've been taught to do.